SENSATION
What is sensation?
Interpreting light touch, pressure, temperature, pain, and vibration through skin
contact / receptors
Distinction between “sensation” and “sensibility”
o latter is used to emphasize functional & interpretative aspects of sensation.
What is the importance of sensation?
Normal sensation is NB for fine and gross motor function and to provide information
about environment
o e.g., the weight, size, and temperature of an object
What is the purpose of sensation assessment?
To assist with finalising a diagnosis
Follow-up assessments to monitor progress after a nerve injury or repair
Assessment for the purposes of compensation
o e.g., medico-legal evaluation
Assessing whether the patient requires therapeutic input
o e.g., compensatory measures, sensation retraining or desensitisation
What are the objectives of sensory assessment following nerve disorders?
To demonstrate regeneration of the nerve and reinnervation of muscles and
cutaneous receptors.
To demonstrate the ability to interpret the new sensory input (i.e., tactile gnosis10),
which requires combined physiologic processes in the peripheral as well as the CNS.
To assess the skills requiring integrated and interacting sensory and motor
functions of the hand that can be expressed as dexterity, grip strength, and
ultimately as ADL capacity.
To quantify the degree of pain and discomfort in terms of hypersensitivity
(discomfort or irritability in response to normal tactile stimulation) and cold intolerance
(pain or discomfort in response to normal exposure to indoor and outdoor
temperatures
What are the outcome domains that are assessed in terms of a PNS injury?
sensory (re-innervation, tactile gnosis, finger dexterity)
motor (innervation, grip strength)
pain and discomfort (pain, hyperaesthesia, cold intolerance)
function (activity and participation)
What are functional changes in sensibility?
Re-innervation → Threshold (minimal stimulus that can be perceived by the patient
in terms of pain, heat, cold, touch / pressure)
Tactile gnosis → Functional sensation; recognition of object shape & texture
Finger dexterity → Performing activities that replicate main hand grips in daily life
What are the different aspects of sensory assessment?
Sensory modalities
Mapping
Threshold
Localization (functional sensation testing)
Influence on function
What are the sensory modalities?
, o Hearing
o Vision
o Taste
o Smell
o Somato-sensory modalities
Light touch
Deep pressure
Pain → ability to perceive superficial / skin-deep pain
Temperature → ability to distinguish between various temperatures
2-point discrimination → ability to distinguish 2 static / moving points
Stereognosis → ability to distinguish between textures and objects
Vibration → ability to perceive vibration.
combination of light touch and deep pressure
not routinely assessed
Proprioception → ability to perceive position of body parts in space
and in relation to each other
Stataesthesia (position sense) → ability to identify limb’s
position in space without visual assistance
Kinesthesia (motion sense) → awareness of motion
What is mapping?
o Assessing the area of sensory loss
o Method
Patient closes eyes
OT moves a blunt object lightly over skin from normal to affected areas
When sensation feels “different”, patient should say “now”
Boundaries are marked on body / assessment form
What is threshold?
o minimal stimulus that can be perceived by the patient in terms of pain, heat,
cold, touch / pressure
What is localization?
o Where stimuli are detected
o Method
Patient closes eyes
OT moves object over skin
Patient indicates point where touched
Correctly localised = indicated with dot on assessment form
Incorrectly localised = arrow drawn from point of application to point of
awareness
What is influence on function?
o impact of the sensory problem / loss of sensation on function
o note compensatory measures
What is sensation?
Interpreting light touch, pressure, temperature, pain, and vibration through skin
contact / receptors
Distinction between “sensation” and “sensibility”
o latter is used to emphasize functional & interpretative aspects of sensation.
What is the importance of sensation?
Normal sensation is NB for fine and gross motor function and to provide information
about environment
o e.g., the weight, size, and temperature of an object
What is the purpose of sensation assessment?
To assist with finalising a diagnosis
Follow-up assessments to monitor progress after a nerve injury or repair
Assessment for the purposes of compensation
o e.g., medico-legal evaluation
Assessing whether the patient requires therapeutic input
o e.g., compensatory measures, sensation retraining or desensitisation
What are the objectives of sensory assessment following nerve disorders?
To demonstrate regeneration of the nerve and reinnervation of muscles and
cutaneous receptors.
To demonstrate the ability to interpret the new sensory input (i.e., tactile gnosis10),
which requires combined physiologic processes in the peripheral as well as the CNS.
To assess the skills requiring integrated and interacting sensory and motor
functions of the hand that can be expressed as dexterity, grip strength, and
ultimately as ADL capacity.
To quantify the degree of pain and discomfort in terms of hypersensitivity
(discomfort or irritability in response to normal tactile stimulation) and cold intolerance
(pain or discomfort in response to normal exposure to indoor and outdoor
temperatures
What are the outcome domains that are assessed in terms of a PNS injury?
sensory (re-innervation, tactile gnosis, finger dexterity)
motor (innervation, grip strength)
pain and discomfort (pain, hyperaesthesia, cold intolerance)
function (activity and participation)
What are functional changes in sensibility?
Re-innervation → Threshold (minimal stimulus that can be perceived by the patient
in terms of pain, heat, cold, touch / pressure)
Tactile gnosis → Functional sensation; recognition of object shape & texture
Finger dexterity → Performing activities that replicate main hand grips in daily life
What are the different aspects of sensory assessment?
Sensory modalities
Mapping
Threshold
Localization (functional sensation testing)
Influence on function
What are the sensory modalities?
, o Hearing
o Vision
o Taste
o Smell
o Somato-sensory modalities
Light touch
Deep pressure
Pain → ability to perceive superficial / skin-deep pain
Temperature → ability to distinguish between various temperatures
2-point discrimination → ability to distinguish 2 static / moving points
Stereognosis → ability to distinguish between textures and objects
Vibration → ability to perceive vibration.
combination of light touch and deep pressure
not routinely assessed
Proprioception → ability to perceive position of body parts in space
and in relation to each other
Stataesthesia (position sense) → ability to identify limb’s
position in space without visual assistance
Kinesthesia (motion sense) → awareness of motion
What is mapping?
o Assessing the area of sensory loss
o Method
Patient closes eyes
OT moves a blunt object lightly over skin from normal to affected areas
When sensation feels “different”, patient should say “now”
Boundaries are marked on body / assessment form
What is threshold?
o minimal stimulus that can be perceived by the patient in terms of pain, heat,
cold, touch / pressure
What is localization?
o Where stimuli are detected
o Method
Patient closes eyes
OT moves object over skin
Patient indicates point where touched
Correctly localised = indicated with dot on assessment form
Incorrectly localised = arrow drawn from point of application to point of
awareness
What is influence on function?
o impact of the sensory problem / loss of sensation on function
o note compensatory measures
